Semipermeable membranes possess a major part in industrial processing technology, commercial and consumer applications. Examples of their applications include, among others, biosensors, transport membranes, drug delivery systems, water purification systems, optical absorbers, and selective separation systems for aqueous and organic liquids carrying dissolved or suspended components.
Semipermeable membranes operate in separation devices by allowing only certain components of a solution or dispersion to preferentially pass through the membrane. Representative examples include U.S. Pat. No. 7,575,687 discloses methods for purifying caustic feed streams using membranes that comprise polysulfonamide matrices. The invention further discloses polysulfonamide membranes which possess a combination of flow, rejection, and caustic stability that make them a viable commercial option for fractionating caustic streams especially generated by a Bayer alumina recovery process.
U.S. Pat. No. 7,909,179 discloses a method for preparing a modified insoluble branched condensation polymer matrix comprising step of treating an insoluble branched condensation polymer matrix comprising reactant residues and having a plurality of primary or secondary amine groups, with a compound of the formula Ar-SO2-X, wherein each X is a leaving group and each Ar is an aryl group or a heteroaryl group.
U.S. Pat. No. 8,092,918 discloses polymer matrices and methods for preparing polymer matrices, as well as methods for purifying caustic feed streams using membranes that comprise polysulfonamide matrices.
There is variety of industrial applications that could benefit from the advantages of membrane technology; membranes possessing the proper and diverse combination of stability and selectivity are available. However a required combination of preforming separation whilst having base stability characteristics is still needed.
Therefore, there is a long felt and unmet need for means and methods of forming a cost-effective alkaline stable membrane for removing impurities from basic streams.